Obviously clear expectations help. I ask for monthly payments in advance. This only works though because "you need me more than I need you" and I'm happy to wa

Obviously clear expectations help. I ask for monthly payments in advance. This only works though because "you need me more than I need you" and I'm happy to walk away (I have other work to do.) This is framed as "risk" (ie, I don't take any, so I don't need to cost it in.) For any kind of "after the fact" payments I assume the risk you won't make the last payment, so I price that in.(ie I jack the price so I've got what j want before the last payment.) I won't start work until you've put some loot in my account. If I start working for free I can expect you to keep moving the goal posts. Since I've already "invested" time in this project I'll be happy to make some changes to get us over the line right? Fundamentally it helps when setting up the partnership, contract, whatever to decide how much risk you want to take on. That comes with experience. But I recommend managing risk carefully. Ideally risk should be balanced. (Getting paid 90 days later, if they feel like it, isn't balanced.) Sometimes I work with them to overcome procurement hurdles. One place could only pay 50% up front, 50% on completion. I doubled the (fixed) price. I got paid up front, their procurement system was happy. I can choose to give a generous settlement discount at the end, or not, depending on their behaviour during the contract etc.